The recently unveiled 2012 BMW 3 Series touted the Head Up display as one its premium features, for this segment. BMW was the first European car builder to adapt head-up display technology – a system initially deployed in aviation and constantly further developed over several decades – for use in volume-production vehicles. The system has been available on the 5 Series since January 2004 and having evolved into a full colour display, takes its place in the 2012 BMW 3 Series.
In terms of graphic representation, functionality and flexibility, the unique new Head-Up Display feature makes a significant contribution towards active safety by displaying driver-relevant information in high-quality resolution within the driver’s direct field of vision, so that he or she does not have to take their eyes off the road. BMW says the crucial gain is in terms of safety. A normal driver takes a whole second to read the speed indicator in the instrument panel or to glance at the navigation device and in that second the vehicle covers a distance of around 14 metres when travelling in urban areas at a speed of 50 km/h.
With the Head-Up Display, the time required by the driver to assimilate information is reduced by more than a half, the system making a decisive contribution towards concentrated and focused driving. The virtual image projected onto the windscreen is perceived as “hovering” at eye level above the bonnet and is visible only to the driver.
This method of displaying information to the driver is less tiring to the eyes since the eye does not have to constantly change between close-range and remote vision. Moreover the brightness of the image adjusts perfectly to the surroundings, so that the eye does not have to readapt each time.
The reproduction of data is effected by means of an intense light source, which is located inside the instrument panel and shines through a translucent TFT (Thin Film Transistor) display, the image being transferred to the windscreen via specially shaped mirrors. Owing to the convex shape and the physical properties of glass, using the windscreen as a reflector is an extremely complex process. In a windscreen, the light path is normally refracted, resulting in double images.
BMW tackles this physical phenomenon with the aid of a wafer-thin foil, which is integrated into the windscreen, ensuring the superimposition of the projected images and, as a result, flawless, undistorted representation. Full-colour Head-Up Display offers the driver a tremendous increase in reading comfort. The complete colour spectrum facilitates a realistic and thus more intuitive display of images and symbols. These speak for themselves, are perceived even faster and do not have to be decoded or interpreted.